Power distribution branch box

Abstract

The invention relates to the technical field of branch boxes, in particular to a power distribution branch box which comprises a branch box body, a cooling module and a dehumidification module, two positioning plates are telescopically and elastically connected in the branch box body, each positioning plate is connected with a wiring terminal in a clamped mode, the cooling module comprises a plurality of evaporation pipes, and the evaporation pipes are connected with the dehumidification module in a clamped mode. The evaporation pipes are connected to the inner walls of the two sides of the branch box body, pipe bodies of the evaporation pipes cover most of the area of the branch box body, an air blower is arranged on the lower side of each side evaporation pipe, the air blowers and the evaporation pipes are connected with a compression pump and a condensation pipe, and the dehumidification module comprises a plurality of water scraping rings and a water storage tank. The water scraping rings are arranged on the evaporation pipes in a sleeving mode, the water scraping rings are driven by a driving mechanism to move up and down in a circulating mode in the axis direction of the evaporation pipes, and the water storage tank is fixedly arranged on the lower sides of the evaporation pipes. According to the technical scheme, on the premise that the stability of electrical components in the box body is guaranteed, the temperature in the box body is reduced, the heat exchange efficiency is improved, and the cooling effect is enhanced.

Description

Technical Field

[0001] This invention relates to the field of branch box technology, and particularly to a power distribution branch box. Background Technology

[0002] Cable distribution boxes are primarily used in power systems to distribute power from the main cable to multiple branch lines. They effectively connect cables and distribute power, while providing overload and short-circuit protection to ensure the safe operation of electrical equipment. Common applications include industrial plants, large buildings, and transportation facilities. Their use ensures the rational distribution of power and prevents damage to equipment caused by cable overload and faults. Cable distribution boxes are typically equipped with switching devices, protective devices, and grounding systems; some high-end models also feature monitoring and alarm functions, enhancing the safety and reliability of the power system.

[0003] During use, the humidity of the environment and the high temperature generated by the cable distribution box itself can affect the contact connection of the terminal blocks. Currently, a common solution is to create ventilation openings in the side walls of the distribution box and use blowers for air cooling to lower the internal temperature, while also using desiccants to reduce moisture. However, moisture carried by airflow can interfere with the contacts, allowing dust or water vapor to enter and affecting the stability and reliability of the connection. Furthermore, desiccants cannot completely dry the entire cavity, and the cold air blown in through the ventilation openings directly affects the electrical components, potentially causing damage. Summary of the Invention

[0004] The main objective of this invention is to provide a power distribution branch box that aims to ensure the stability of electrical components inside the box, reduce the internal temperature of the box, improve heat exchange efficiency, and enhance the cooling effect.

[0005] To achieve the above objectives, the present invention provides a power distribution branch box, comprising: The branch box has two retractable and elastically connected positioning plates, and each positioning plate is snapped with a wiring terminal. The cooling module includes several evaporation tubes, each of which is connected to the inner wall of both sides of the branch box. The evaporation tubes cover most of the area of ​​the branch box. A blower is provided on the lower side of each evaporation tube. The blower and the evaporation tube are connected to a compressor pump and a condenser tube. The dehumidification module includes several wiper rings and a water storage tank. Each wiper ring is fitted onto each evaporator tube and is driven by a drive mechanism to move up and down cyclically along the axis of the evaporator tube. The water storage tank is fixedly installed on the lower side of the evaporator tube to collect water droplets on the evaporator tube.

[0006] In one possible implementation, the wiper ring is arranged in a spiral with multiple turns centered on the axis of the evaporator tube.

[0007] In one possible implementation, the wiper ring has wiper grooves.

[0008] In one possible implementation, the driving mechanism includes a driving plate and a driving member. The driving plate is fixedly connected to several adjacent evaporation tubes. Each driving plate has a driving disk abutting on one side. The non-center position of each driving disk abuts against the groove of the adjacent driving plate. The driving member is used to drive the driving disk to rotate.

[0009] In one possible implementation, a dustproof plate is fixedly connected inside the branch box, and the dustproof plate has several elongated ventilation slots.

[0010] In one possible implementation, a limit cylinder is fixedly connected between the branch box and the inner wall of the positioning plate.

[0011] In one possible implementation, two calipers are slidably connected to the back of the positioning plate, and a spring post is fixedly connected between the two calipers. A linkage plate is hinged to the upper side of the two calipers, and two linkage slots are opened on the linkage plate. The end of each caliper that is close to the linkage plate abuts against the inner wall of the linkage slot. A handle is fixedly connected to the linkage plate, and several locking blocks are fixedly connected to the terminal block. Several locking slots are opened on the side of each locking block facing the adjacent caliper.

[0012] This invention combines cooling and dehumidification modules to precisely regulate the temperature and humidity within the branch box, ensuring a stable environment and thus guaranteeing the stable operation and extended lifespan of components. The cooling module utilizes the synergistic effect of the evaporator tube and blower to lower the surface temperature of the evaporator tube below the air dew point, causing water vapor in the air to condense into water droplets. As water droplets accumulate, the surface temperature of the evaporator tube decreases, effectively enhancing heat exchange efficiency and improving cooling performance. Furthermore, with the assistance of the dehumidification component, the timely removal of water droplets facilitates smoother heat exchange between the evaporator tube surface and the gas inside the branch box, thereby improving cooling efficiency and further ensuring a stable working environment for the components inside the box. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of a power distribution branch box according to the present invention. Figure 1 ; Figure 2 for Figure 1 Enlarged diagram of A in the middle; Figure 3 This is a schematic diagram of a power distribution branch box according to the present invention. Figure 2 ; Figure 4 for Figure 3 Enlarged diagram of B in the diagram; Figure 5 This is a schematic diagram of a power distribution branch box with a prominent positioning plate according to the present invention. Figure 1 ; Figure 6 This is a schematic diagram of a power distribution branch box with a prominent positioning plate according to the present invention. Figure 2 ; Figure 7 for Figure 6 An enlarged diagram of C in the diagram.

[0015] Explanation of icon numbers: 11. Branch box; 12. Positioning plate; 13. Terminal block; 14. Evaporator tube; 15. Blower; 16. Squeegee ring; 161. Squeegee groove; 17. Water tank; 21. Drive plate; 22. Drive disc; 23. Dustproof plate; 24. Ventilation slot; 31. Limit cylinder; 32. Caliper; 33. Spring column; 34. Link plate; 35. Link groove; 36. Handle; 37. Locking block; 38. Locking slot.

[0016] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0018] This invention proposes a power distribution branch box.

[0019] Example 1 Reference Figures 1 to 7The system includes a branch box 11, a cooling module, and a dehumidification module. Two positioning plates 12 are retractably and elastically connected inside the branch box 11. Terminal blocks 13 are snapped onto the positioning plates 12. The cooling module includes several evaporation tubes 14, each connected to the inner walls on both sides of the branch box 11. The tubes of the evaporation tubes 14 cover most of the area of ​​the branch box 11. Each blower 15 is located below the evaporation tubes 14. Both the blowers 15 and the evaporation tubes 14 are connected to a compressor pump and a condenser. The dehumidification module includes several scraper rings 16 and a water tank 17. Each scraper ring 16 is fitted onto each evaporation tube 14. The scraper rings 16 are driven by a drive mechanism and move up and down cyclically along the axis of the evaporation tube 14. The water tank 17 is fixedly located below the evaporation tubes 14 to collect water droplets on the evaporation tubes 14.

[0020] Firstly, by combining the cooling and dehumidification modules, the temperature and humidity inside the branch box 11 are precisely controlled to ensure a stable internal environment, thereby guaranteeing the stable operation of internal components and extending their service life. Specifically, the cooling module, through the coordinated operation of the evaporator tube 14 and the blower 15, and with the support of the compressor pump, lowers the surface temperature of the evaporator tube 14 to below the dew point of the air inside the branch box 11. When the surface temperature of the evaporator tube 14 is sufficiently low, water vapor in the air begins to condense into water droplets on the surface of the evaporator tube 14 and gradually accumulates. When the water droplets accumulate to a certain extent, they slide down the cylindrical surface of the evaporator tube 14. This process effectively reduces the internal temperature of the box and improves the heat exchange efficiency between the air and the surface of the evaporator tube, thereby enhancing the cooling effect.

[0021] Meanwhile, the dehumidification module plays a crucial role in this process. With the help of the scraper ring 16, condensate is promptly scraped off, preventing excessively large water droplets from dripping into the chamber and potentially affecting the equipment. The scraper ring 16 moves axially along the evaporator tube 14, effectively preventing water droplet accumulation and thus maintaining the dual effects of cooling and dehumidification. Because the water droplets are removed promptly, heat exchange between the surface of the evaporator tube 14 and the gas inside the branch chamber 11 is smoother, thereby improving cooling efficiency and further ensuring a stable operating environment for the components inside the chamber.

[0022] To prevent overuse of the cooling and dehumidification modules, the system is equipped with humidity and temperature monitoring devices. These devices can monitor humidity and temperature changes inside the enclosure in real time and automatically adjust the system's operating status according to set standards. Precise control of humidity and temperature prevents damage to components caused by excessive temperature and humidity fluctuations, effectively extending their lifespan. Furthermore, intelligent humidity and temperature control ensures optimized energy consumption, avoiding unnecessary resource waste.

[0023] Through the above design, the entire system can reduce equipment wear while ensuring effective cooling and dehumidification, maintaining optimal temperature and humidity within the branch box, and ultimately providing effective protection for components and extending their service life. This sophisticated control system provides an ideal working environment for modern electronic equipment, not only improving its reliability and stability but also laying the foundation for its long-term efficient operation.

[0024] In addition, to further optimize humidity management, a drain outlet is designed on the outside of the water storage tank 17. When the ambient humidity of the branch box 11 is high, and a large amount of water vapor accumulates in the water storage tank 17 in a short period of time, the water vapor will condense into water inside the tank and quickly fill it. In this case, the system will automatically drain the excess water through a drain pipe located at the top of the water storage tank 17. This drainage process can continue until the water level in the water storage tank 17 drops to a safe range.

[0025] Water discharged through the pipes can be smoothly introduced into the local sewer system, preventing water from flowing back into the branch tank 11, thus effectively reducing the replenishment of humidity to the surrounding environment. This design not only ensures the effective discharge of water vapor from the water tank but also avoids excessive humidity caused by water retention, thereby further optimizing the humidity control function of the entire system.

[0026] The system's self-regulation capability has been enhanced, ensuring that in high-humidity environments, the system can efficiently drain excess moisture and maintain stable humidity within the branch box 11. This precise humidity management effectively prevents equipment damage due to excessive moisture, improving the system's long-term stability and reliability.

[0027] Furthermore, it is worth noting that each evaporator tube 14 is designed to be installed on the inner walls of both sides of the branch box 11, covering most of the area of ​​the branch box 11. The tube body of the evaporator tube 14 is large enough to ensure that most areas inside the branch box 11 can benefit from its heat exchange effect, thereby effectively reducing the internal temperature of the box and improving the overall cooling effect. To optimize airflow and heat exchange, the blower 15 is designed to blow directly onto the evaporator tube 14, rather than directly onto the components themselves. This design has two main purposes: first, to prevent dust in the air from being blown directly onto the components, avoiding short circuits or other damage caused by dust accumulation; second, to prevent moisture from being blown directly onto the contact points of the components, preventing short circuits caused by moisture accumulation and ensuring that the components operate in a stable environment. This effectively solves the safety problem of components in high humidity environments, and at the same time, improves the cooling efficiency of the system through optimized airflow and heat exchange systems. The large coverage of the evaporator tube 14 and the precise airflow direction of the blower 15 not only improve the cooling effect, but also ensure the stability and long-term reliability of the components. This sophisticated design not only avoids potential failure risks but also ensures that the system can operate stably in changing working environments.

[0028] Furthermore, the water tank 17 not only serves as a water vapor collection device but also acts as a counterweight, helping to maintain the stability of the branch box 11. Because the water tank 17 stores water, its weight effectively increases the overall mass of the branch box 11, ensuring that it will not tilt or become unstable due to external vibrations or environmental changes during operation. This design allows the branch box 11 to be stably positioned in its designated location, preventing mechanical damage or equipment failure caused by instability. This function not only improves equipment safety but also reduces reliance on additional support structures, making the overall design more compact and efficient. Simultaneously, the water tank 17's design as a counterweight makes the entire system more stable and reliable during operation, contributing to improved long-term stability and durability.

[0029] Reference Figure 3 and Figure 4 The driving mechanism includes a driving plate 21 and a driving component. The driving plate 21 is fixedly connected to several adjacent evaporation tubes 14. One side of each driving plate 21 abuts against the driving disk 22. The non-center position on each driving disk 22 abuts against the groove of the adjacent driving plate 21. The driving component is used to drive the driving disk 22 to rotate.

[0030] The rotation of the drive disk 22 is precisely controlled by the drive component in the drive plate mechanism. The drive component is preferably a stepper motor, which ensures the driving effect while reducing the cost of the motor. The wiper ring 16 can move stably up and down along the axis of the evaporation tube 14. The condensation on the outer wall of the evaporation tube 14 is removed by the up and down movement of the wiper ring 16, and then flows down the outer wall of the evaporation tube 14 into the water storage tank 17 for collection, preventing the moisture from evaporating again and spreading into the air, thereby avoiding the impact of excessive humidity on the equipment inside the branch box 11.

[0031] The drive mechanism enables the wiper ring 16 to move at the right time, ensuring efficient removal of condensation beads and preventing moisture buildup, thus maintaining a suitable working environment. Precise wiping action not only prevents moisture from re-evaporating but also effectively reduces potential risks such as corrosion of electrical components and short circuits caused by excessive moisture.

[0032] Furthermore, the system design ensures that the humidity within the branch box 11 remains within a stable and reasonable range, thereby guaranteeing the long-term stable operation of all components. Because humidity is effectively controlled, the components inside the branch box 11 are less susceptible to the effects of a humid environment, improving the equipment's efficiency and reliability. In summary, effective humidity management ensures the normal operation of all components within the branch box 11, preventing moisture damage to the equipment and avoiding potential hazards to electrical components.

[0033] Reference Figures 1 to 3 The dustproof plate 23 is fixedly connected inside the branch box 11, and several slender ventilation slots 24 are opened on the dustproof plate 23.

[0034] The dustproof plate 23 effectively blocks humidity and dust inside the branch box 11, providing an effective solution, especially in the presence of moisture. When the humidity inside the branch box 11 is high, the humidity around the evaporator pipe 14 will concentrate due to condensation, forming a relatively humid environment. This moisture will adversely affect electrical components such as the wiring terminals 13, increasing the risk of short circuits or corrosion.

[0035] To address this issue, a blower 15 is installed below the evaporator pipe 14. The airflow from the blower 15, guided by the dust-proof plate 23, effectively controls the direction of moisture flow, preventing it from spreading to other areas. The dust-proof plate 23 not only provides physical isolation but also guides airflow, ensuring moisture is concentrated in a specific area. Furthermore, the ventilation slot 24 guides the airflow speed, making the ventilation process more efficient. Through Bernoulli's principle, the airflow speed increases within the ventilation slot 24, creating a flowing airflow between the two dust-proof plates 23. This airflow helps moisture flow to both sides, preventing moisture concentration from affecting the wiring terminal 13 and nearby electrical components.

[0036] This ensures that the environment inside the branch box 11 remains dry, effectively reducing the potential impact of moisture on the wires and terminals 13, and preventing electrical faults or damage caused by moisture. By controlling airflow, the dustproof plate 23 and the ventilation slot 24 work together to enable the terminals 13 and other electrical components to operate normally in a stable, dry environment, improving the reliability and operational stability of the equipment.

[0037] Overall, this design not only effectively prevents the spread of moisture and the intrusion of dust, but also optimizes airflow and humidity management, thereby enhancing the long-term operational stability of the internal components of the branch box 11.

[0038] Reference Figures 1 to 6 A limit cylinder 31 is fixedly connected between the branch box 11 and the positioning plate 12.

[0039] The limiting cylinder 31, preferably a hydraulic cylinder, allows the user to easily adjust the distance between the branch box 11 and the positioning plate 12. This design is particularly suitable for handling branch boxes 11 with greater depth. When the branch box 11 is deep, the user or worker does not need to bend excessively to enter the box during operation, significantly reducing the difficulty of operation and enhancing the comfort of working, making the assembly process easier and more efficient.

[0040] Furthermore, for some shallower branch boxes 11, the limit cylinder 31 still plays an important role. Users can remove the terminal block 13 from the branch box 11, facilitating the locking of the contacts on the terminal block 13. This makes it easier for workers to install the terminal block 13, circuit breakers, and other accessories. Adjusting the hydraulic cylinder ensures that workers are in a suitable position, avoiding discomfort that may result from prolonged low-posture operation, and greatly improving operational flexibility and accuracy.

[0041] In summary, the workspace can be flexibly adjusted according to different cabinet depths to adapt to various installation needs. This not only improves work efficiency and shortens installation time, but also ensures operational safety and comfort, avoiding unnecessary labor intensity for workers in confined spaces. Furthermore, the precise control of the limit cylinder 31 provides stable support during operation, ensuring that workers can perform various installation tasks more meticulously and guaranteeing the accurate installation and fixation of components.

[0042] Reference Figures 5 to 7Two calipers 32 are slidably connected to the back of the positioning plate 12. A spring post 33 is fixedly connected between the two calipers 32. The center section of the spring post 33 is fixedly connected to the back of the positioning plate 12. A linkage plate 34 is hinged to the upper side of the two calipers 32. Two linkage grooves 35 are opened on the linkage plate 34. The end of each caliper 32 that is close to the linkage plate 34 abuts against the inner wall of the linkage groove 35. The linkage plate 34 is fixedly connected to the handle 36. Several locking blocks 37 are fixedly connected to the terminal block 13. Several locking grooves 38 are opened on the side of the locking block 37 facing the adjacent caliper 32.

[0043] By applying a downward force to the handle 36, the user can easily operate the device. The handle 36 is connected to the linkage plate 34. Driven by the linkage plate 34, the two calipers 32 move in opposite directions, thereby separating the calipers 32 from the locking block 37. This loosens the connection between the terminal 13 and the locking block 37, allowing free movement of the terminal 13. After the user adjusts the terminal 13 to the appropriate position, the handle can be released. With the restoring force of the spring column 33, the two calipers 32 will automatically reset, re-clamp the locking block 37, and stabilize the height position of the terminal 13 through the limiting effect of the calipers 32.

[0044] The positioning and connection process of the terminal block 13 is simplified, allowing users or workers to install or adjust more conveniently and quickly. Through the force of the spring column 33, the pressure applied by the caliper 32 to the locking block 37 acts as a shear force on the slot on the positioning plate 12, ensuring that the locking block 37 is stably positioned within the slot. However, the stroke of the spring column 33 is precisely limited, effectively controlling the range of movement of the locking block 37 and preventing excessive offset or deformation of the locking block 37 during the positioning process, thereby maintaining a stable fit between the components.

[0045] This effectively ensures that the terminal block 13 can be stably placed at the set height, avoiding malfunctions or instability that may be caused by component deformation or inaccurate positioning. The entire process not only improves installation accuracy and efficiency but also enhances operational safety and reliability, ensuring the long-term stable operation of the terminal block 13.

[0046] Example 2 This embodiment improves upon embodiment 1 by modifying the wiper ring 16; Reference Figures 1 to 7 The scraper ring 16 is arranged in a spiral with multiple turns centered on the axis of the evaporator tube 14.

[0047] By designing the wiper ring 16 in a spiral pattern, the heat exchange area between the evaporator tube 14 and the air can be effectively expanded, thereby improving the condensation efficiency of the evaporator tube 14. The spiral layout allows the wiper ring 16 to cover a wider area, ensuring more uniform and sufficient contact between the air and the cooling surface, thus accelerating the formation of condensate droplets and effectively reducing the air temperature within the branch box 11. Simultaneously, this design effectively shortens the vertical travel of the wiper ring 16, thereby reducing the workload and energy consumption of the drive components. By reducing the load on the drive system, not only is the energy efficiency of the equipment improved, but the service life of the drive components is also extended, reducing maintenance frequency and costs.

[0048] Furthermore, the spiral-shaped wiper ring 16 exhibits significant advantages in guiding water droplets. Condensed water droplets flow smoothly along the shape of the wiper ring 16 without accumulating or overflowing. The water droplets are effectively diverted and guided to the water tank 17 for collection, thus avoiding water waste and ensuring a dry environment inside the branch housing 11. This design not only improves the overall dehumidification effect but also ensures the system's efficient and stable operation. By optimizing the shape and structure of the wiper ring 16, the technical effect is significantly enhanced, condensate management is more precise, and the long-term efficient operation of the dehumidifier is ensured.

[0049] Reference Figures 1 to 4 The wiper groove 161 is formed on the wiper ring 16.

[0050] The design of the scraper groove 161 further optimizes the accumulation and removal process of condensate droplets on the surface of the evaporator tube 14. This design effectively prevents water droplets from overflowing from the scraper ring 16 during scraping operation, ensuring that the condensate droplets can smoothly slide down the cylindrical surface on the outer side of the scraper ring 16. This prevents water droplets from overflowing or splashing, allowing them to smoothly slide into the water storage tank 17 below for collection and storage. It also ensures the dryness of the internal environment of the branch box 11. Optimizing the water droplet removal efficiency of the evaporator tube 14 enhances the overall operational stability of the system and helps improve the dehumidification effect and the heat exchange effect between the evaporator tube 14 and the internal gas of the branch box 11.

[0051] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0052] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A power distribution branch box, characterized in that, include: Branch box (11), inside which are retractable elastically connected two positioning plates (12), each of which is fitted with a terminal block (13). The cooling module includes several evaporation tubes (14), each of which is connected to the inner walls on both sides of the branch box (11). The tube body of the evaporation tube (14) covers most of the area of ​​the branch box (11). A blower (15) is provided on the lower side of each evaporation tube (14). The blower (15) and the evaporation tube (14) are connected to a compressor pump and a condenser. The dehumidification module includes several scraper rings (16) and a water tank (17). Each scraper ring (16) is sleeved on each evaporator tube (14). The scraper ring (16) is driven by a drive mechanism and moves up and down cyclically along the axis of the evaporator tube (14). The water tank (17) is fixedly installed on the lower side of the evaporator tube (14) to collect water droplets on the evaporator tube (14).

2. The power distribution branch box according to claim 1, characterized in that, The shape of the scraper ring (16) is arranged in a spiral with the axis of the evaporator tube (14) as the center.

3. The power distribution branch box according to claim 2, characterized in that, The wiper ring (16) has a wiper groove (161).

4. The power distribution branch box according to claim 1, characterized in that, The driving mechanism includes a driving plate (21) and a driving component. The driving plate (21) is fixedly connected to several adjacent evaporation tubes (14). Each driving plate (21) has a driving disk (22) on one side. The non-center position on each driving disk (22) abuts against the groove of the adjacent driving plate (21). The driving component is used to drive the driving disk (22) to rotate.

5. The power distribution branch box according to claim 1, characterized in that, A dustproof plate (23) is fixedly connected inside the branch box (11), and several slender ventilation slots (24) are provided on the dustproof plate (23).

6. The power distribution branch box according to claim 1, characterized in that, A limit cylinder (31) is fixedly connected between the branch box (11) and the inner wall of the positioning plate (12).

7. The power distribution branch box according to claim 1, characterized in that, The positioning plate (12) has two calipers (32) slidably connected to its back. A spring column (33) is fixedly connected between the two calipers (32). A linkage plate (34) is hinged to the upper side of the two calipers (32). Two linkage grooves (35) are opened on the linkage plate (34). The end of each caliper (32) that is close to the linkage plate (34) abuts against the inner wall of the linkage groove (35). A handle (36) is fixedly connected to the linkage plate (34). Several locking blocks (37) are fixedly connected to the terminal block (13). Several locking grooves (38) are opened on the side of each locking block (37) facing the adjacent caliper (32).

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